Methods of forming nitride dielectric layers having reduced exposure to oxygen

Abstract

of A method of forming a dielectric layer includes the steps of forming an electrode on a microelectronic substrate, and forming depressions and protrusions on exposed portions of the electrode thereby increasing a surface area thereof. An exposed portion of the electrode including the depressions and protrusions is nitrified, and the electrode is not exposed to oxygen during and between the steps of forming the depressions and protrusions and nitrifying the exposed portion of the electrode. A nitride layer is then formed on a nitrified electrode. Related structures are also discussed.

That which is claimed is: 
     
       1. A method of forming a dielectric layer, said method comprising the steps of: forming a silicon electrode on a microelectronic substrate;   forming depressions and protrusions on an exposed portion of said silicon electrode thereby increasing a surface area thereof;   nitrifying said exposed portion of said silicon electrode including said depressions and protrusions wherein said silicon electrode is not exposed to oxygen during and between said step of forming said depressions and protrusions and said step of nitrifying said exposed portion of said silicon electrode; and   forming a nitride layer on said nitrified silicon electrode;   wherein said step of forming said depressions and protrusions on said exposed portion of said silicon electrode and said step of nitrifying said exposed portion of said silicon electrode are performed in-situ in a common processing chamber.   
     
     
       2. A method according to claim 1 wherein said step of forming said depressions and protrusions comprises forming a hemispherical grained silicon layer on said electrode. 
     
     
       3. A method according to claim 2 wherein said step of forming said hemispherical grained silicon layer comprises seeding said exposed portion of said electrode with a seed gas including silicon, and performing a thermal treatment on said seeded electrode. 
     
     
       4. A method according to claim 1 wherein said step of forming said depressions and protrusions comprises seeding metallic particles on said exposed portion of said electrode and performing a thermal treatment on said exposed portion of said electrode. 
     
     
       5. A method according to claim 4 wherein said nitrifying step is followed by the step of removing said metallic particles from portions of said substrate surrounding said electrode. 
     
     
       6. A method according to claim 5 wherein said removing step comprises a wet etch. 
     
     
       7. A method according to claim 4 wherein said metallic particles react with said exposed portion of said electrode to form a silicide during said thermal treatment. 
     
     
       8. A method according to claim 4 wherein said metallic particles comprise a metal chosen from the group consisting of tungsten (W) and titanium (Ti). 
     
     
       9. A method according to claim 4 wherein said seeding step is performed at a temperature in the range of 100° C. to 1000° C. 
     
     
       10. A method according to claim 4 wherein said thermal treatment is performed at a temperature in the range of 600° C. to 1000° C. 
     
     
       11. A method according to claim 1 wherein said step of forming said depressions and protrusions comprises exciting said exposed portion of said electrode and performing a thermal treatment on said exposed portion of said electrode. 
     
     
       12. A method according to claim 11 wherein said step of exciting said exposed portion of said electrode comprises providing a plasma discharge adjacent said exposed portion of said electrode. 
     
     
       13. A method according to claim 12 wherein said step of providing said plasma discharge comprises providing a plasma discharge of a gas chosen from the group consisting of helium (He), hydrogen (H), argon (Ar), and nitrogen (N). 
     
     
       14. A method according to claim 11 wherein said step of providing said plasma discharge comprises providing a plasma discharge of a gas including an element chosen from the group consisting of arsenic (As) and phosphorous (P). 
     
     
       15. A method according to claim 11 wherein said exciting step comprises irradiating said exposed portion of said electrode with ultraviolet radiation. 
     
     
       16. A method according to claim 11 wherein said thermal treatment is performed at a temperature in the range of 600° C. to 1000° C. 
     
     
       17. A method according to claim 1 wherein said step of forming said depressions and protrusions and said step of nitrifying said exposed portion of said electrode are performed separately in separate processing chambers within a multi-chamber processing system including a vacuum loadlock chamber for transferring said substrate between said separate processing chambers. 
     
     
       18. A method according to claim 1 wherein said electrode comprises amorphous silicon. 
     
     
       19. A method according to claim 18 wherein said amorphous silicon electrode is doped with phosphorous. 
     
     
       20. A method according to claim 1 wherein said step of nitrifying said exposed portion of said electrode comprises providing a nitrogen containing gas adjacent said electrode while heating said electrode. 
     
     
       21. A method according to claim 1 wherein said nitrifying step comprises discharging a plasma including nitrogen adjacent said exposed portion of said electrode including said depressions and protrusions. 
     
     
       22. A method according to claim 1 wherein said nitrifying step comprises providing a nitrogen containing gas adjacent said electrode while heating said electrode and discharging a plasma adjacent said electrode. 
     
     
       23. A method according to claim 1 wherein said nitrifying step and said step of forming said nitride layer a performed in-situ in a common reaction chamber. 
     
     
       24. A method according to claim 1 wherein said step of forming said nitride layer is followed by the step of oxidizing a surface of said nitride layer opposite said electrode. 
     
     
       25. A method according to claim 1 wherein said step of forming said electrode is preceded by the step of: forming an insulating layer on said microelectronic substrate wherein said insulating layer has a contact hole therein exposing a portion of said substrate and wherein said electrode is electrically coupled with said exposed portion of said substrate through said contact hole.   
     
     
       26. A method according to claim 1 further comprising the step of: forming a second electrode on said nitride layer opposite said first electrode.   
     
     
       27. A method of forming a dielectric layer, said method comprising the steps of: forming a silicon electrode on a microelectronic substrate;   forming depressions and protrusions on an exposed portion of said silicon electrode thereby increasing a surface area thereof;   nitrifying said exposed portion of said silicon electrode including said depressions and protrusions wherein said silicon electrode is not exposed to oxygen during and between said step of forming said depressions and protrusions and said step of nitrifying said exposed portion of said silicon electrode; and   forming a nitride layer on said nitrified silicon electrode;   wherein said step of forming said depressions and protrusions and said step of nitrifying said exposed portion of said electrode are performed separately in separate processing chambers within a multi-chamber processing system including a vacuum loadlock chamber for transferring said substrate between said separate processing chambers.